1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cryptographic API.
4 *
5 * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
6 *
7 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
9 *
10 * The HMAC implementation is derived from USAGI.
11 * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
12 */
13
14#include <crypto/hmac.h>
15#include <crypto/internal/hash.h>
16#include <linux/err.h>
17#include <linux/fips.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21#include <linux/string.h>
22
23struct hmac_ctx {
24 struct crypto_shash *hash;
25 /* Contains 'u8 ipad[statesize];', then 'u8 opad[statesize];' */
26 u8 pads[];
27};
28
29struct ahash_hmac_ctx {
30 struct crypto_ahash *hash;
31 /* Contains 'u8 ipad[statesize];', then 'u8 opad[statesize];' */
32 u8 pads[];
33};
34
35static int hmac_setkey(struct crypto_shash *parent,
36 const u8 *inkey, unsigned int keylen)
37{
38 int bs = crypto_shash_blocksize(tfm: parent);
39 int ds = crypto_shash_digestsize(tfm: parent);
40 int ss = crypto_shash_statesize(tfm: parent);
41 struct hmac_ctx *tctx = crypto_shash_ctx(tfm: parent);
42 struct crypto_shash *hash = tctx->hash;
43 u8 *ipad = &tctx->pads[0];
44 u8 *opad = &tctx->pads[ss];
45 SHASH_DESC_ON_STACK(shash, hash);
46 int err, i;
47
48 if (fips_enabled && (keylen < 112 / 8))
49 return -EINVAL;
50
51 shash->tfm = hash;
52
53 if (keylen > bs) {
54 int err;
55
56 err = crypto_shash_digest(desc: shash, data: inkey, len: keylen, out: ipad);
57 if (err)
58 return err;
59
60 keylen = ds;
61 } else
62 memcpy(to: ipad, from: inkey, len: keylen);
63
64 memset(s: ipad + keylen, c: 0, n: bs - keylen);
65 memcpy(to: opad, from: ipad, len: bs);
66
67 for (i = 0; i < bs; i++) {
68 ipad[i] ^= HMAC_IPAD_VALUE;
69 opad[i] ^= HMAC_OPAD_VALUE;
70 }
71
72 err = crypto_shash_init(desc: shash) ?:
73 crypto_shash_update(desc: shash, data: ipad, len: bs) ?:
74 crypto_shash_export(desc: shash, out: ipad) ?:
75 crypto_shash_init(desc: shash) ?:
76 crypto_shash_update(desc: shash, data: opad, len: bs) ?:
77 crypto_shash_export(desc: shash, out: opad);
78 shash_desc_zero(desc: shash);
79 return err;
80}
81
82static int hmac_export(struct shash_desc *pdesc, void *out)
83{
84 struct shash_desc *desc = shash_desc_ctx(desc: pdesc);
85
86 return crypto_shash_export(desc, out);
87}
88
89static int hmac_import(struct shash_desc *pdesc, const void *in)
90{
91 struct shash_desc *desc = shash_desc_ctx(desc: pdesc);
92 const struct hmac_ctx *tctx = crypto_shash_ctx(tfm: pdesc->tfm);
93
94 desc->tfm = tctx->hash;
95
96 return crypto_shash_import(desc, in);
97}
98
99static int hmac_export_core(struct shash_desc *pdesc, void *out)
100{
101 struct shash_desc *desc = shash_desc_ctx(desc: pdesc);
102
103 return crypto_shash_export_core(desc, out);
104}
105
106static int hmac_import_core(struct shash_desc *pdesc, const void *in)
107{
108 const struct hmac_ctx *tctx = crypto_shash_ctx(tfm: pdesc->tfm);
109 struct shash_desc *desc = shash_desc_ctx(desc: pdesc);
110
111 desc->tfm = tctx->hash;
112 return crypto_shash_import_core(desc, in);
113}
114
115static int hmac_init(struct shash_desc *pdesc)
116{
117 const struct hmac_ctx *tctx = crypto_shash_ctx(tfm: pdesc->tfm);
118
119 return hmac_import(pdesc, in: &tctx->pads[0]);
120}
121
122static int hmac_update(struct shash_desc *pdesc,
123 const u8 *data, unsigned int nbytes)
124{
125 struct shash_desc *desc = shash_desc_ctx(desc: pdesc);
126
127 return crypto_shash_update(desc, data, len: nbytes);
128}
129
130static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
131 unsigned int nbytes, u8 *out)
132{
133
134 struct crypto_shash *parent = pdesc->tfm;
135 int ds = crypto_shash_digestsize(tfm: parent);
136 int ss = crypto_shash_statesize(tfm: parent);
137 const struct hmac_ctx *tctx = crypto_shash_ctx(tfm: parent);
138 const u8 *opad = &tctx->pads[ss];
139 struct shash_desc *desc = shash_desc_ctx(desc: pdesc);
140
141 return crypto_shash_finup(desc, data, len: nbytes, out) ?:
142 crypto_shash_import(desc, in: opad) ?:
143 crypto_shash_finup(desc, data: out, len: ds, out);
144}
145
146static int hmac_init_tfm(struct crypto_shash *parent)
147{
148 struct crypto_shash *hash;
149 struct shash_instance *inst = shash_alg_instance(shash: parent);
150 struct crypto_shash_spawn *spawn = shash_instance_ctx(inst);
151 struct hmac_ctx *tctx = crypto_shash_ctx(tfm: parent);
152
153 hash = crypto_spawn_shash(spawn);
154 if (IS_ERR(ptr: hash))
155 return PTR_ERR(ptr: hash);
156
157 tctx->hash = hash;
158 return 0;
159}
160
161static int hmac_clone_tfm(struct crypto_shash *dst, struct crypto_shash *src)
162{
163 struct hmac_ctx *sctx = crypto_shash_ctx(tfm: src);
164 struct hmac_ctx *dctx = crypto_shash_ctx(tfm: dst);
165 struct crypto_shash *hash;
166
167 hash = crypto_clone_shash(tfm: sctx->hash);
168 if (IS_ERR(ptr: hash))
169 return PTR_ERR(ptr: hash);
170
171 dctx->hash = hash;
172 return 0;
173}
174
175static void hmac_exit_tfm(struct crypto_shash *parent)
176{
177 struct hmac_ctx *tctx = crypto_shash_ctx(tfm: parent);
178
179 crypto_free_shash(tfm: tctx->hash);
180}
181
182static int __hmac_create_shash(struct crypto_template *tmpl,
183 struct rtattr **tb, u32 mask)
184{
185 struct shash_instance *inst;
186 struct crypto_shash_spawn *spawn;
187 struct crypto_alg *alg;
188 struct shash_alg *salg;
189 int err;
190 int ds;
191 int ss;
192
193 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
194 if (!inst)
195 return -ENOMEM;
196 spawn = shash_instance_ctx(inst);
197
198 mask |= CRYPTO_AHASH_ALG_NO_EXPORT_CORE;
199 err = crypto_grab_shash(spawn, inst: shash_crypto_instance(inst),
200 name: crypto_attr_alg_name(rta: tb[1]), type: 0, mask);
201 if (err)
202 goto err_free_inst;
203 salg = crypto_spawn_shash_alg(spawn);
204 alg = &salg->base;
205
206 /* The underlying hash algorithm must not require a key */
207 err = -EINVAL;
208 if (crypto_shash_alg_needs_key(alg: salg))
209 goto err_free_inst;
210
211 ds = salg->digestsize;
212 ss = salg->statesize;
213 if (ds > alg->cra_blocksize ||
214 ss < alg->cra_blocksize)
215 goto err_free_inst;
216
217 err = crypto_inst_setname(shash_crypto_instance(inst), "hmac",
218 "hmac-shash", alg);
219 if (err)
220 goto err_free_inst;
221
222 inst->alg.base.cra_priority = alg->cra_priority;
223 inst->alg.base.cra_blocksize = alg->cra_blocksize;
224 inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) + (ss * 2);
225
226 inst->alg.digestsize = ds;
227 inst->alg.statesize = ss;
228 inst->alg.descsize = sizeof(struct shash_desc) + salg->descsize;
229 inst->alg.init = hmac_init;
230 inst->alg.update = hmac_update;
231 inst->alg.finup = hmac_finup;
232 inst->alg.export = hmac_export;
233 inst->alg.import = hmac_import;
234 inst->alg.export_core = hmac_export_core;
235 inst->alg.import_core = hmac_import_core;
236 inst->alg.setkey = hmac_setkey;
237 inst->alg.init_tfm = hmac_init_tfm;
238 inst->alg.clone_tfm = hmac_clone_tfm;
239 inst->alg.exit_tfm = hmac_exit_tfm;
240
241 inst->free = shash_free_singlespawn_instance;
242
243 err = shash_register_instance(tmpl, inst);
244 if (err) {
245err_free_inst:
246 shash_free_singlespawn_instance(inst);
247 }
248 return err;
249}
250
251static int hmac_setkey_ahash(struct crypto_ahash *parent,
252 const u8 *inkey, unsigned int keylen)
253{
254 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm: parent);
255 struct crypto_ahash *fb = crypto_ahash_fb(tfm: tctx->hash);
256 int ds = crypto_ahash_digestsize(tfm: parent);
257 int bs = crypto_ahash_blocksize(tfm: parent);
258 int ss = crypto_ahash_statesize(tfm: parent);
259 HASH_REQUEST_ON_STACK(req, fb);
260 u8 *opad = &tctx->pads[ss];
261 u8 *ipad = &tctx->pads[0];
262 int err, i;
263
264 if (fips_enabled && (keylen < 112 / 8))
265 return -EINVAL;
266
267 ahash_request_set_callback(req, flags: 0, NULL, NULL);
268
269 if (keylen > bs) {
270 ahash_request_set_virt(req, src: inkey, result: ipad, nbytes: keylen);
271 err = crypto_ahash_digest(req);
272 if (err)
273 goto out_zero_req;
274
275 keylen = ds;
276 } else
277 memcpy(to: ipad, from: inkey, len: keylen);
278
279 memset(s: ipad + keylen, c: 0, n: bs - keylen);
280 memcpy(to: opad, from: ipad, len: bs);
281
282 for (i = 0; i < bs; i++) {
283 ipad[i] ^= HMAC_IPAD_VALUE;
284 opad[i] ^= HMAC_OPAD_VALUE;
285 }
286
287 ahash_request_set_virt(req, src: ipad, NULL, nbytes: bs);
288 err = crypto_ahash_init(req) ?:
289 crypto_ahash_update(req) ?:
290 crypto_ahash_export(req, out: ipad);
291
292 ahash_request_set_virt(req, src: opad, NULL, nbytes: bs);
293 err = err ?:
294 crypto_ahash_init(req) ?:
295 crypto_ahash_update(req) ?:
296 crypto_ahash_export(req, out: opad);
297
298out_zero_req:
299 HASH_REQUEST_ZERO(req);
300 return err;
301}
302
303static int hmac_export_ahash(struct ahash_request *preq, void *out)
304{
305 return crypto_ahash_export(req: ahash_request_ctx(req: preq), out);
306}
307
308static int hmac_import_ahash(struct ahash_request *preq, const void *in)
309{
310 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req: preq);
311 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm);
312 struct ahash_request *req = ahash_request_ctx(req: preq);
313
314 ahash_request_set_tfm(req, tfm: tctx->hash);
315 return crypto_ahash_import(req, in);
316}
317
318static int hmac_export_core_ahash(struct ahash_request *preq, void *out)
319{
320 return crypto_ahash_export_core(req: ahash_request_ctx(req: preq), out);
321}
322
323static int hmac_import_core_ahash(struct ahash_request *preq, const void *in)
324{
325 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req: preq);
326 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm);
327 struct ahash_request *req = ahash_request_ctx(req: preq);
328
329 ahash_request_set_tfm(req, tfm: tctx->hash);
330 return crypto_ahash_import_core(req, in);
331}
332
333static int hmac_init_ahash(struct ahash_request *preq)
334{
335 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req: preq);
336 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm);
337
338 return hmac_import_ahash(preq, in: &tctx->pads[0]);
339}
340
341static int hmac_update_ahash(struct ahash_request *preq)
342{
343 struct ahash_request *req = ahash_request_ctx(req: preq);
344
345 ahash_request_set_callback(req, flags: ahash_request_flags(req: preq),
346 compl: preq->base.complete, data: preq->base.data);
347 if (ahash_request_isvirt(req: preq))
348 ahash_request_set_virt(req, src: preq->svirt, NULL, nbytes: preq->nbytes);
349 else
350 ahash_request_set_crypt(req, src: preq->src, NULL, nbytes: preq->nbytes);
351 return crypto_ahash_update(req);
352}
353
354static int hmac_finup_finish(struct ahash_request *preq, unsigned int mask)
355{
356 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req: preq);
357 struct ahash_request *req = ahash_request_ctx(req: preq);
358 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm);
359 int ds = crypto_ahash_digestsize(tfm);
360 int ss = crypto_ahash_statesize(tfm);
361 const u8 *opad = &tctx->pads[ss];
362
363 ahash_request_set_callback(req, flags: ahash_request_flags(req: preq) & ~mask,
364 compl: preq->base.complete, data: preq->base.data);
365 ahash_request_set_virt(req, src: preq->result, result: preq->result, nbytes: ds);
366 return crypto_ahash_import(req, in: opad) ?:
367 crypto_ahash_finup(req);
368
369}
370
371static void hmac_finup_done(void *data, int err)
372{
373 struct ahash_request *preq = data;
374
375 if (err)
376 goto out;
377
378 err = hmac_finup_finish(preq, CRYPTO_TFM_REQ_MAY_SLEEP);
379 if (err == -EINPROGRESS || err == -EBUSY)
380 return;
381
382out:
383 ahash_request_complete(req: preq, err);
384}
385
386static int hmac_finup_ahash(struct ahash_request *preq)
387{
388 struct ahash_request *req = ahash_request_ctx(req: preq);
389
390 ahash_request_set_callback(req, flags: ahash_request_flags(req: preq),
391 compl: hmac_finup_done, data: preq);
392 if (ahash_request_isvirt(req: preq))
393 ahash_request_set_virt(req, src: preq->svirt, result: preq->result,
394 nbytes: preq->nbytes);
395 else
396 ahash_request_set_crypt(req, src: preq->src, result: preq->result,
397 nbytes: preq->nbytes);
398 return crypto_ahash_finup(req) ?:
399 hmac_finup_finish(preq, mask: 0);
400}
401
402static int hmac_digest_ahash(struct ahash_request *preq)
403{
404 return hmac_init_ahash(preq) ?:
405 hmac_finup_ahash(preq);
406}
407
408static int hmac_init_ahash_tfm(struct crypto_ahash *parent)
409{
410 struct ahash_instance *inst = ahash_alg_instance(ahash: parent);
411 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm: parent);
412 struct crypto_ahash *hash;
413
414 hash = crypto_spawn_ahash(spawn: ahash_instance_ctx(inst));
415 if (IS_ERR(ptr: hash))
416 return PTR_ERR(ptr: hash);
417
418 if (crypto_ahash_reqsize(tfm: parent) < sizeof(struct ahash_request) +
419 crypto_ahash_reqsize(tfm: hash))
420 return -EINVAL;
421
422 tctx->hash = hash;
423 return 0;
424}
425
426static int hmac_clone_ahash_tfm(struct crypto_ahash *dst,
427 struct crypto_ahash *src)
428{
429 struct ahash_hmac_ctx *sctx = crypto_ahash_ctx(tfm: src);
430 struct ahash_hmac_ctx *dctx = crypto_ahash_ctx(tfm: dst);
431 struct crypto_ahash *hash;
432
433 hash = crypto_clone_ahash(tfm: sctx->hash);
434 if (IS_ERR(ptr: hash))
435 return PTR_ERR(ptr: hash);
436
437 dctx->hash = hash;
438 return 0;
439}
440
441static void hmac_exit_ahash_tfm(struct crypto_ahash *parent)
442{
443 struct ahash_hmac_ctx *tctx = crypto_ahash_ctx(tfm: parent);
444
445 crypto_free_ahash(tfm: tctx->hash);
446}
447
448static int hmac_create_ahash(struct crypto_template *tmpl, struct rtattr **tb,
449 u32 mask)
450{
451 struct crypto_ahash_spawn *spawn;
452 struct ahash_instance *inst;
453 struct crypto_alg *alg;
454 struct hash_alg_common *halg;
455 int ds, ss, err;
456
457 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
458 if (!inst)
459 return -ENOMEM;
460 spawn = ahash_instance_ctx(inst);
461
462 mask |= CRYPTO_AHASH_ALG_NO_EXPORT_CORE;
463 err = crypto_grab_ahash(spawn, inst: ahash_crypto_instance(inst),
464 name: crypto_attr_alg_name(rta: tb[1]), type: 0, mask);
465 if (err)
466 goto err_free_inst;
467 halg = crypto_spawn_ahash_alg(spawn);
468 alg = &halg->base;
469
470 /* The underlying hash algorithm must not require a key */
471 err = -EINVAL;
472 if (crypto_hash_alg_needs_key(alg: halg))
473 goto err_free_inst;
474
475 ds = halg->digestsize;
476 ss = halg->statesize;
477 if (ds > alg->cra_blocksize || ss < alg->cra_blocksize)
478 goto err_free_inst;
479
480 err = crypto_inst_setname(ahash_crypto_instance(inst), tmpl->name, alg);
481 if (err)
482 goto err_free_inst;
483
484 inst->alg.halg.base.cra_flags = alg->cra_flags &
485 CRYPTO_ALG_INHERITED_FLAGS;
486 inst->alg.halg.base.cra_flags |= CRYPTO_ALG_REQ_VIRT;
487 inst->alg.halg.base.cra_priority = alg->cra_priority + 100;
488 inst->alg.halg.base.cra_blocksize = alg->cra_blocksize;
489 inst->alg.halg.base.cra_ctxsize = sizeof(struct ahash_hmac_ctx) +
490 (ss * 2);
491 inst->alg.halg.base.cra_reqsize = sizeof(struct ahash_request) +
492 alg->cra_reqsize;
493
494 inst->alg.halg.digestsize = ds;
495 inst->alg.halg.statesize = ss;
496 inst->alg.init = hmac_init_ahash;
497 inst->alg.update = hmac_update_ahash;
498 inst->alg.finup = hmac_finup_ahash;
499 inst->alg.digest = hmac_digest_ahash;
500 inst->alg.export = hmac_export_ahash;
501 inst->alg.import = hmac_import_ahash;
502 inst->alg.export_core = hmac_export_core_ahash;
503 inst->alg.import_core = hmac_import_core_ahash;
504 inst->alg.setkey = hmac_setkey_ahash;
505 inst->alg.init_tfm = hmac_init_ahash_tfm;
506 inst->alg.clone_tfm = hmac_clone_ahash_tfm;
507 inst->alg.exit_tfm = hmac_exit_ahash_tfm;
508
509 inst->free = ahash_free_singlespawn_instance;
510
511 err = ahash_register_instance(tmpl, inst);
512 if (err) {
513err_free_inst:
514 ahash_free_singlespawn_instance(inst);
515 }
516 return err;
517}
518
519static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
520{
521 struct crypto_attr_type *algt;
522 u32 mask;
523
524 algt = crypto_get_attr_type(tb);
525 if (IS_ERR(ptr: algt))
526 return PTR_ERR(ptr: algt);
527
528 mask = crypto_algt_inherited_mask(algt);
529
530 if (!((algt->type ^ CRYPTO_ALG_TYPE_AHASH) &
531 algt->mask & CRYPTO_ALG_TYPE_MASK))
532 return hmac_create_ahash(tmpl, tb, mask);
533
534 if ((algt->type ^ CRYPTO_ALG_TYPE_SHASH) &
535 algt->mask & CRYPTO_ALG_TYPE_MASK)
536 return -EINVAL;
537
538 return __hmac_create_shash(tmpl, tb, mask);
539}
540
541static int hmac_create_shash(struct crypto_template *tmpl, struct rtattr **tb)
542{
543 u32 mask;
544 int err;
545
546 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, mask_ret: &mask);
547 if (err)
548 return err == -EINVAL ? -ENOENT : err;
549
550 return __hmac_create_shash(tmpl, tb, mask);
551}
552
553static struct crypto_template hmac_tmpls[] = {
554 {
555 .name = "hmac",
556 .create = hmac_create,
557 .module = THIS_MODULE,
558 },
559 {
560 .name = "hmac-shash",
561 .create = hmac_create_shash,
562 .module = THIS_MODULE,
563 },
564};
565
566static int __init hmac_module_init(void)
567{
568 return crypto_register_templates(tmpls: hmac_tmpls, ARRAY_SIZE(hmac_tmpls));
569}
570
571static void __exit hmac_module_exit(void)
572{
573 crypto_unregister_templates(tmpls: hmac_tmpls, ARRAY_SIZE(hmac_tmpls));
574}
575
576module_init(hmac_module_init);
577module_exit(hmac_module_exit);
578
579MODULE_LICENSE("GPL");
580MODULE_DESCRIPTION("HMAC hash algorithm");
581MODULE_ALIAS_CRYPTO("hmac");
582